Description

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1901 edition. Excerpt: ...and magnitudes of magnetic storms occurring while a spot remained at not less than half its maximum measured magnitude; that is, during the period when each spot was approaching and receding from its maximum area. The last table gives the number and magnitudes of magnetic storms, together with the corresponding total spotted area of the Sun's visible hemisphere. These two tables taken together show: (1) that both large and small spots may be unaccompanied by magnetic storms, but that the smaller spots are more frequently so than the larger oneg; (2) that the smaller spots may be accompanied by considerable magnetic disturbances. '"On the Connection between Solar Spots and Earth-magnetic Storms." By Rev. Walter Sidgreaves, S. J., F. R. A. S., Stonyhurst College Observatory. Repr. Memoirs Royal Astronomical Society, Vol. LIV, London, 1901. 23x31 cm, pp. 85-96. The author mentions two very decided magnetic storms which occurred at the beginning and end of November, 1889, and were unaccompanied by Sun-sp'ots. He states his conclusion in the following words: "It seems therefore true that recorded observations, while clearly asserting a real connection bet1veen Sun-spots and magnetic storms, are against any theory which places the cause of magnetic disturbances within or near the Sun; and consequently that the real connection must be through a common cause of both--something moving, which may pass by or near the Sun or near the Earth, and at times near enough to both to produce the two effects together." Wm. F. Wall1s. CHANGE OF MAGNETIC MOMENT BY SHOCK. An account of experiments by Kruese in which bar magnets were subjected to violeut treatment and the resulting change of magnetic moment measured. The results are given in tables....show more